- From: Simon St.Laurent <simonstl@simonstl.com>
- Date: Tue, 08 May 2001 09:23:22 -0400
- To: www-xml-linking-comments@w3.org
In section 4.3 of the 8 January 2001 XPointer Working Draft (http://www.w3.org/TR/xptr#schemes), the following appears: >Each XPtrPart begins with a Scheme that identifies the particular notation >used for that XPtrPart. This specification defines only two schemes, >xpointer and xmlns, and reserves all others when the media type of the >referenced resource is one of text/xml, application/xml, >text/xml-external-parsed-entity, or >application/xml-external-parsed-entity. However, the scheme mechanism >provides a general framework for extensibility that can be used for future >versions of XPointer, or for other media types that wish to adopt all or >part of this specification in defining their own fragment identifier >languages. I'm concerned that developers with needs other than the complete set of XPointer functionality are poorly served by the current single and unversioned xpointer scheme. It seems like an xpath scheme - which only contained XPaths and not the extensions XPointer provides - would allow developers to use XLink for node-to-node hypertext applications at much lower cost than understanding and implementing the full range of possibilities in XPointer. Applications which fully understood XPointer would also understand the XPath scheme, but they could provide additional functionality. Applications which only understood XPath would be able to point to the xpointer() content of the URI and explain that they didn't understand it. This approach would allow more considerably more functionality than is required (http://www.w3.org/TR/xptr#app-conformance) by minimal conformance, while still not imposing the larger costs of full conformance. It seems like schemes are a useful tool for encouraging diversity, but the XPointer specification in its current form does not appear to apply it that way. If it were possible - and I'm aware certain people believe changes neither possible nor valuable - it seems like it might be reasonable to publish one document creating an XPointer framework. This would contain the material required by minimal conformance, possibly child sequences, the rules for the xmlns scheme, and rules for creating other schemes. That could be published immediately as XPointer 1.0. The details of what goes in XPointer could then be reserved for explanations of the schemes, and it seems reasonable to suggest that multiple schemes are possible and probably even to be encouraged. Simon St.Laurent - Associate Editor, O'Reilly & Associates XML Elements of Style / XML: A Primer, 2nd Ed. XHTML: Migrating Toward XML http://www.simonstl.com - XML essays and books
Received on Tuesday, 8 May 2001 09:23:14 UTC